The U.S. State Department says it will take immediate action to put North Korea back on its list of terrorism sponsor states, if there's credible evidence under the "statutory criteria."

According to the Voice of America on Friday, East Asian and Pacific Affairs Spokeswoman Katina Adams said that the department consistently reviews intelligence on the North.

This comes after 12 U.S. senators -- six Republicans and six Democrats -- requested the designation, at the urging of the parents of Otto Warmbier, an American student who died earlier this year after being detained in the North for almost a year-and-a-half.

Currently, three countries -- Iran, Syria and Sudan -- are listed on Washington's list of countries that sponsor terrorism. 

North Korea was included in the list for 20 years from 1988 until it was removed by the George W. Bush administration when Pyongyang agreed to dismantle a plutonium plant.

[Photo : ]